1. Field of the Invention
The present invention relates to a combination of a thermal transfer film and a thermally sensitive color developing paper capable of easily recording a plurality of colors on the thermally sensitive color developing paper, a composite thermal transfer sheet composed of them and a recording method using the same, in particular, those for recording a plurality of colors on the thermally sensitive color developing paper by utilizing the difference of recorded hues with a low energy and with a high energy in a large printer dedicated for a thermally sensitive color developing paper.
2. Description of the Related Art
Conventionally, there have been proposed various kinds of multi-color recording methods using a thermally fusible transfer sheet having a thermal transfer coloring layer with a coloring agent such as a pigment and a dye dispersed in a binder such as a thermally fusible wax and a resin.
For example, examples of a two-color recording with a combination of a thermally fusible transfer sheet and a thermally sensitive color developing paper can be presented as follows.
Japanese Patent Application Laid-Open (JP-A) No. Sho-56-157395 discloses a combination of a thermally sensitive color developing paper that starts color development at a temperature lower than the melting point of a thermal transfer ink, and a thermally fusible transfer sheet having a thermal transfer ink of a hue different from that of the color development, in which they are brought into contact with each other. Moreover, Japanese Patent Application Laid-Open (JP-A) No. Sho-59-42996 discloses a method of superimposing a thermally sensitive color developing paper that starts color development at a temperature higher than the transfer temperature of a thermal transfer ink, and a thermally fusible transfer sheet having a thermal transfer ink of a hue different from that of the color development, obtaining the thermal transfer ink hue by heating at a low temperature, and obtaining a mixed color of the thermal transfer ink and the developed color of the thermally sensitive color developing paper by heating at a high temperature.
As the similar methods thereto, Japanese Patent Application Laid-Open (JP-A) No. Hei-3-234669 as a high temperature color developing paper type. Further, Japanese Patent Application Laid-Open (JP-A) No. Hei-7-186543 as a high temperature color developing paper type method first forming a color developed image on a thermally sensitive color developing paper, and then transferring a thermal transfer ink from a thermally fusible transfer sheet can be presented.
In the conventional methods, the primal shortcoming is that a preferable black color cannot be recorded but a reddish black color, or the like is recorded by a color mixture of a bright color (in particular, a reddish color) and a dark color (for example, black color) at the time of black recording with a high energy.
Moreover, Japanese Patent Application Laid-Open (JP-A) No. Sho-61-61891 comprises a first ink layer for developing and transferring a color onto a substrate at a predetermined heating temperature, and a second ink layer disposed on the first ink layer for transferring at a heating temperature lower than the predetermined heating temperature.
Japanese Patent Application Laid-Open (JP-A) No. Sho-59-136286 comprises a combination of a transfer sheet provided with a high temperature transfer layer and a low temperature transfer layer containing a leuco dye for developing a color different from that of the high temperature transfer layer successively on a substrate, and a receiving sheet having a receptor layer containing a color developing agent, wherein an anti-coloring agent is contained either in the high temperature transfer layer or in an intermediate layer between the high temperature transfer layer and the low temperature transfer layer.
Furthermore, various methods with a multi-plies (multi-layered) thermally fusible transfer sheet have been proposed.
For example, Japanese Patent Application Laid-Open (JP-A) No. Sho-61-61892 discloses a multi-plies thermally fusible ink layer with the melting points thereof lowered from the substrate side to the surface layer side gradually. Although a multi-plies configuration of the transfer layers of a thermally fusible transfer sheet has been adopted, in either case, it is extremely difficult to control the applied energy for controlling the transfer amount for each transferable ply in the multi-plies transfer layer.
Moreover, Japanese Patent Application Laid-Open (JP-A) No. Sho-55-97983 discloses a method of providing a thermal transfer sheet in which a thermally sensitive color developing layer transferable is disposed on a substrate, and also providing an image receiving sheet having a receptor layer containing solid fatty acids and/or solid fatty acid amides, and applying a heat treatment after transferring the thermally sensitive color developing layer so as to improve the printing density (substantially monochrome printing density).
Furthermore, as a method for two-color recording, Japanese Patent Application Laid-Open (JP-A) No. Sho-61-137789 discloses a method for achieving two-color printing on a member to be recorded by superimposing a thermal transfer sheet provided with a thermally fusible first ink layer and a thermally fusible second ink layer of different tones, and a member to be recorded, and changing the time of peeling them off after printing. According to the method, the load of the software and the hardware for controlling the peel-off time on a printer machine is high. Furthermore, a printer dedicated for a thermally sensitive color developing paper does not have a peeling off mechanism in most cases, and thus it cannot be applied practically.
Accordingly, in view of the above-mentioned problems, an object of the prevent invention is to achieve vivid recording of a bright color and a dark color easily by one thermal transfer film to be loaded on a printer dedicated for a thermally sensitive color developing paper without a winding up mechanism for a thermal transfer film by varying the applied energy.
In order to achieve the above-mentioned object, the present invention provides, as one aspect, a combination of a thermal transfer film and a thermally sensitive color developing paper.
In a first embodiment of the combination, the thermal transfer film is provided with a thermally fusible ink layer to be transferred onto the thermally sensitive color developing paper on one surface of a substrate film, and the thermally sensitive color developing paper is capable of developing a color of a hue different from that of the thermally fusible ink layer of the thermal transfer film,
wherein a red hue can be recorded on the thermally sensitive color developing paper by the transfer of the thermally fusible ink or by the developed color of the thermally sensitive color developing paper in the case the applied energy is relatively low,
a plurality of colors can be recorded on the thermally sensitive color developing paper according to color mixture of the transfer of the thermally fusible ink and the developed color of the thermally sensitive color developing paper in the case the applied energy is relatively high, and
a* is 40 to 70, b* is 0 to 25, and C* is 40 to 75 in the red hue recorded by the transfer of the thermally fusible ink or by the developed color of the thermally sensitive color developing paper, and a* is 0 to 20, b* is 0 to 10, and C* is 0 to 20 in the black hue recorded by the color mixture of the transfer of the thermally fusible ink and the developed color of the thermally sensitive color developing paper.
Use of the first embodiment of the combination according to the present invention makes it possible to vividly and easily record a bright color and a dark color by one thermal transfer film.
In the first embodiment of the combination, in the case the thermally fusible ink layer of the thermal transfer film has a red hue, it is preferable that the thermally sensitive color developing paper is capable of generating a black hue of |a*|xe2x89xa65 and |b*|xe2x89xa63.
In a second embodiment of the combination, the thermal transfer film is provided with a thermally fusible ink layer to be transferred onto the thermally sensitive color developing paper on one surface of a substrate film,
wherein the thermally fusible ink layer contains at least one selected from the group consisting of blue, green, red, purple, and black pigments, and
the thermally sensitive color developing paper is capable of developing a color with hue of any one selected from the group consisting of black, blue, and red, which is different from the hue of the thermally fusible ink layer of the thermal transfer film.
It can be loaded on a printer dedicated for a thermally sensitive color developing paper as well as multi-color recording can be enabled easily by varying the applied energy. That is, in the case the applied energy is low, the hue of only the thermal transfer ink layer or the hue of only the developed color of the thermally sensitive color developing paper can be recorded, or in the case the applied energy is high, the hue of a color mixture of the transfer from the thermal transfer ink layer and the developed color of the thermally sensitive color developing paper can be recorded by one thermal transfer film.
In the case the thermal transfer ink layer of the thermal transfer film is capable of recording a blue hue on the thermally sensitive color developing paper by transferring the thermal transfer ink on said color developing paper at a temperature lower than a color developing temperature of said color developing paper or in the case the thermally sensitive color developing paper is capable of recording a blue hue at a temperature lower than thermally transferring temperature of said thermal transfer film, it is preferable that the blue hue recorded in a printing part of the color developing paper when applying a low energy has a* in a range of 0 to 30, b* in a range of xe2x88x9240 to xe2x88x9270, and C* in a range of 30 to 77.
Further in this case, when the applied energy is high, it is preferable to record a black hue on the thermally sensitive color developing paper by a color mixture of the transfer from the thermal transfer ink layer and the developed color of the thermally sensitive color developing paper, and the black hue recorded by the color mixture preferably has a* in a range of xe2x88x9210 to 10, b* in a range of xe2x88x9215 to 10, and C* in a range of 0 to 18.
In the other case the thermal transfer ink layer of the thermal transfer film is capable of recording a purple hue on the thermally sensitive color developing paper by transferring the thermal transfer ink on said color developing paper at a temperature lower than a color developing temperature of said color developing paper, it is preferable that the purple hue recorded in a printing part of the color developing paper when applying a low energy has a* in a range of 30 to 50, b* in a range of xe2x88x9230 to xe2x88x9250, and C* in a range of 42 to 71.
Further in this case, when the applied energy is high, it is preferable to record a black hue on the thermally sensitive color developing paper by a color mixture of the transfer from the thermal transfer ink layer and the developed color of the thermally sensitive color developing paper, and the obtained black hue recorded by the color mixture preferably has a* in a range of xe2x88x9210 to 20, b* in a range of xe2x88x9215 to 10, and C* in a range of 0 to 25.
In the still other case the thermal transfer ink layer of the thermal transfer film is capable of recording a green hue on the thermally sensitive color developing paper by transferring the thermal transfer ink on said color developing paper at a temperature lower than a color developing temperature of said color developing paper, it is preferable that the green hue recorded in a printing part of the color developing paper when applying a low energy has a* in a range of xe2x88x9240 to xe2x88x9270, b* in a range of xe2x88x9215 to 5, and C* in a range of 0 to 72.
Further in this case, when the applied energy is high, it is preferable to record a blue hue on the thermally sensitive color developing paper by a color mixture of the transfer from the thermal transfer ink layer and the developed color of the thermally sensitive color developing paper, and the obtained blue hue recorded by the color mixture preferably has a* in a range of xe2x88x925 to 15, b* in a range of xe2x88x9270 to xe2x88x9230, and C* in a range of 30 to 72.
It is preferable for the first and the second embodiment of the combination that a pigment of a C. I. Pigment red 177 or C. I. Pigment blue 15:4 is contained in the thermal transfer ink layer of the above-mentioned thermal transfer film. By containing a pigment of the C. I. Pigment red 177 or a C. I. Pigment blue 15:4 in the thermal transfer ink layer of the thermal transfer film, a vivid hue can be obtained. Moreover, it is preferable to contain a black pigment in the thermal transfer ink layer.
Moreover, it is preferable that any of the above-mentioned embodiments are provided as a composite thermal transfer sheet in which the thermal transfer film and the thermally sensitive color developing paper are peelably bonded together with the thermally fusible ink layer and the color developing surface facing to each other. Furthermore, they can be provided as a composite thermal transfer sheet with a temporary adhesive layer disposed between the thermal transfer film and the thermally sensitive color developing paper.
The present invention also provides, as the other aspect, a recording method of heating a thermal transfer film and a thermally sensitive color developing paper brought into contact with each other by using the above described combinations, in particular, the composite type.
In a first embodiment of the recording method according to the present invention, any one of the combination described above is used in such manner that the hue of the thermal transfer ink layer is recorded on the thermally sensitive color developing paper in the case the applied energy from the heating device is low, and a plurality of colors is recorded on the thermally sensitive color developing paper by color mixture of the transfer from the thermal transfer ink layer and the developed color of the thermally sensitive color developing paper in the case the applied energy is high.
In a second embodiment of the recording method according to the present invention, any one of the combination described above is used in such manner that the hue of the developed color of the thermally sensitive color developing paper is recorded in the case the applied energy from the heating device is low, and a plurality of colors is recorded on the thermally sensitive color developing paper by color mixture of the transfer from the thermal transfer ink layer and the developed color of the thermally sensitive color developing paper in the case the applied energy is high.